/Engine/Source/Runtime/MovieScene/Public/EntitySystem/MovieSceneEntityFactory.h
include "EntitySystem/MovieSceneEntityFactoryTemplates.h" for definition
template<typename ParentComponent, typename ChildComponent, typename InitializerCallback> void DefineChildComponent ( [TComponentTypeID](API\Runtime\MovieScene\EntitySystem\TComponentTypeID)< ParentComponent > InParentType, [TComponentTypeID](API\Runtime\MovieScene\EntitySystem\TComponentTypeID)< ChildComponent > InChildType, InitializerCallback && InInitializer )